var user={name:"1",age:21,qq:"3333"};
console.log("name:%s",user.name);
console.log("age:%d",user.age);
console.log("qq:%j",user.qq);
function longTask(){
    for(var i= 0;i<10000;i++){
        for(var j=0;j<10000;j++){
            var n=i*j;
        }
    }
}

console.time("test");
longTask();
console.timeEnd("test");